Three years ago, Zeph's age was 25% of Ben's age. Five years from their current age, Zeph's age will be 37.5% of Ben's age. How many years is Ben older than Zeph?
| |
Zeph |
Ben |
Difference |
| Before |
1x5 =
5 u |
4x5 =
20 u |
3x5 =
15 u |
| Change |
+ 3
+ 5 |
+ 3
+ 5 |
|
| After |
3x3 =
9 u |
8x3 =
24 u |
5x3 =
15 u |
25% =
25100 =
14 37.5% =
3751000 =
38The difference in the ages between Zeph and Ben remains unchanged. Make the difference the same. LCM of 3 and 5 is 15.
Increase in Zeph's age
= 9 u - 5 u
= 4 u
4 u = 3 + 5
4 u = 8
1 u = 8 ÷ 4 = 2
Number of years that Ben is older than Zeph
= 20 u - 5 u
= 15 u
= 15 x 2
= 30
Answer(s): 30
